Robert Redford’s first directorial effort since his 2007 anti-war polemic Lions for Lambs is a striking Civil War courtroom drama not far removed from a film like Bruce Beresford’s Breaker Morant. The assassination of President Lincoln calls into question the possible participation of Mary Surratt (Robin Wright), the mother of a young man who befriended John Wilkes Booth and his accomplices. It was inside the boarding house Mary Surratt owned and operated where Booth and his men planned the attacks on Lincoln. Hot for revenge, the state seeks the death penalty and tries the accused civilians in a Washington, D.C., military tribunal rather than in a civil court.

In yet another wonderfully designed portrayal in a career of memorable performances James McAvoy plays Frederick Aiken, a young Union war-hero-turned-attorney. Aiken is assigned on the day before the trial begins to defend Mary Surratt, whose sought-after son John vanished two weeks before the assassination. McAvoy’s ice-water American accent divulges the precision of his character’s ability to comprehend complexities of the case before him. He is genuinely heroic.

Clear connections between the U.S. Government’s modern-day attack on civil liberties and the Constitution are at the heart of the story. Kevin Kline’s pernicious Secretary of War Edwin Stanton goes to any lengths to see his personal brand of political expediency exerted over Mary Surratt regardless of a dearth of evidence against her.

Newbie screenwriter James Solomon develops the touchy relationship between Aiken and Mary Surratt as a window inside Aiken’s thorny process of setting aside his biases against a person who should be considered innocent until proven guilty. Aiken too is predisposed against Surratt as a guilty accomplice until he begins to comprehend the limited extent of her involvement in what was initially planned to be a kidnap attempt. It takes a while for him (and for us) to accept Mary Surratt as a real human being. Robin Wright soars to dramatic heights in her restrained performance. The effect is reminiscent of Jessica Lange’s finest work. Between them, McAvoy and Wright carry the drama to its farthest recesses of innate social consciousness. Left to the wolves by her son, Mary Surratt is supported by Aiken’s compassion.

The Conspirator misses the mark in several areas. A lack of narrative attention to the circumstances of the planning by Booth and his men, that went on in Mary Surratt’s boarding house, nag at the story. The other accused are set up as props rather than as integral parts of the story. And the look of the film is clinically staged to a near-soap opera brand of visual wash.

Mary Surratt’s mistreatment at the hands of the United States federal system remains a black eye on a legal process whose conditions remain as susceptible to influence today as they were in 1865.

THE CONSPIRATOR (3) •Directed by Robert Redford • Starring Robin Wright, James McAvoy, Kevin Kline •Rated PG-13 • 122 min •At Osio Cinemas.